SCP idea~
The idea was for an entity that appears in people's dreams occasionally, hiding in crowds or behind a window of an abandoned building. It isn't able to be contained, because it only exists in people's dreams, but, it could be studied and documented.
The documentation log would become increasingly strange and creepy eventually just becoming NOPE NOPE NOPE just like that.

Maybe it could just be the brain's way of trying to tell you something.
Or, maybe it's it's own entity altogether :/

You need more hook.
Dreams are weird, poorly understood, and universally relatable so they make a good jumping off point. But the flipside is that you need something really spectacular to diferentiate your scp from the million and one other real-dream stories that have been done, from australian aborigine "dreamtime" to Freddy Krueger.

Some things to consider:
-How would the Foundation spot this? There are already many common themes and archetypes that recur in nearly eveyone's dreams at least occasionally, what makes this one stand out? See Jung.
-How does it threaten normalcy? Even if there is a real BEM peeping dreams around the world, why would the Foundation care? The random public would tend to just dismiss it as an odd dream, and a strange coincidence that other people have had similar dreams. What makes the Foundation care enough to devote resources?

I was thinking of it more on a "it's actually your subconscious warning you of your eventual death" kind of stand point. Also, why does it feel that every good idea anywhere has already been used in some way? If feels like the website is reading my mind!